毕业论文外文翻译—关于SBS改性沥青配合比设计及施工技术的探讨.doc

关于sbs改性沥青配合比设计及施工技术的探讨 摘要在良好的设计配合比和施工条件下，sbs沥青能使沥青路面的耐久性和高温稳定性明显提高。本文将根据南二路的施工试验情况，简要讲述sbs改性沥青的施工技术要求。一、sbs改性沥青概述 sbs改性沥青是在原有基质沥青（ah-70）的基础上，掺加2.5%、3.0%、4.0的sbs改性剂，改性后的沥青，与原沥青相比，其高温粘度增大，软化点升高。在良好的设计配合比和施工条件下，沥青路面的耐久性和高温稳定性明显提高。在sbs改性沥青生产过程中进行了大量的室内试验，生产后对其技术指标进行了现场实验，实验结果表明，外掺3.0%sbs的改性沥青，软化点、针入度等指标均满足改性沥青规范要求，可用sbs改性沥青做沥青混合料的配合比设计。二、sbs沥青混合料的配合比设计 为了使设计的混合料能够达到实施效果，需要从材料要求、施工工艺、质量控制标准和质量控制方法等诸多方面提出以下要求，希望能够引起注意。（一）、原材料要求1-1粗集料：用于改性沥青混合料面层的粗集料，宜采用碎石或碎砾石，其粒径规格和质量要求均应符合公路沥青路面施工技术规范（jtj032-94）的规定1.粗集料应洁净、干燥、无风化、无有害杂质，且具有一定硬度和强度。2.粗集料应具有良好的颗粒形状，破碎砾石用于高速公路、一级公路时，应采用大砾石破碎，并至少应有两个以上的破碎面。3、对于抗滑表层粗集料应选择硬质岩（中性或基性火成岩）。由于硬质岩石与沥青的粘接力存在着较大差异，粗集料与沥青的粘附性应不小于4级。对于35mm石屑部分由于含量较低，并且该部分对沥青混合料形成嵌接结构有一定的作用，建议用硬质岩石屑（玄武岩）。1-2细集料细集料包括人工砂、天然砂。沥青路面面层宜采用人工砂作为细集料，细集料应洁净、干燥、无风化、无有害杂质，有适当的颗粒组成，并与改性沥青有良好的粘附性，天然砂由于质量变化大（大部分为中粗砂），形状较圆滑，与沥青的粘附性差，对沥青混合料影响较大。对于高速公路、一级公路沥青混合料，天然砂的含量不宜超过20，可用0-3mm的石屑粉代替天然砂。1-3填充料用于改性沥青混合料面层的填料应洁净、干燥，其质量应符合公路沥青路面技术规范规定的技术要求。1、改性沥青混合料填充料宜采用强基性岩石（石灰岩、岩浆岩）等增水性石料经磨细得到的矿粉，矿粉要求干燥、洁净，不宜使用混合料生产中干法除尘的回收粉。2、采用水泥、消石灰粉做填料时，其用量不宜超过矿料总量的2%。3、对于沥青表面层混合料不推荐使用在混合料生产排回收粉，当塑性指数小于4且亲水系数小于0.8时，经过试验可以部分的使用，回收粉用量每盘不能超过矿粉总量的四分之一。（二）、沥青混合料配合比设计：改性沥青混合料的配合比设计，应遵循公路沥青路面施工技术规范中关于热拌沥青混合料配合比设计的目标配合比、生产配合比及试拌试铺的三个阶段，确定矿料级配及最佳改性沥青用量。2-1级配沥青混合料配合比设计级配应采用贝雷法进行设计，级配选择原则：ac-13i型混合料2.36mm以下筛孔通过量应取级配下限以达到密实、嵌挤。2-2粉料比小于0.075mm含量的多少对沥青混合料体积指标和路用性能影响很大，混合料级配中小于0.075mm的含量必须考虑粗集料本应含有的粉尘部分。要求矿粉含量不超过沥青含量，小于0.075mm部分与沥青含量之间的比值即粉料比应存在11.2之间，对沥青面层混合料矿粉含量宜取4.55。2-3注意事项:改性沥青混和料的设计过程中以下问题上引起注意。a、混和料的拌合和击实温度应根据改性沥青路面施工技术规范和根据沥青胶结料的粘温关系曲线进行确定，进行室内配合比设计时的拌合、击实温度应与拌合厂拌合温度、现场碾压温度一致。建议温度见下表：改性沥青的试验和施工温度：温度密级配沥青混合料拌合温度不小于160；初压温度不小于150；复压温度不小于140；终压温度不小于120。b、试验取样和拌合时要保证沥青胶结料的均匀性，应将制备好的胶结料拌合均匀后进行取样和混合料的制备。c、混合料体积指标的测定要统一，对于密级配沥青混合料试件密度的测定应统一采用表干法。d、改性沥青混合料的水稳定性应符合以下两个指标要求，达不到要求时应采取抗剥落措施：(1)、采用“沥青混合料马歇尔稳定度试验”方法测定的48h浸水马歇尔稳定度试验残留稳定度不应小于80%。（2）、采用“沥青混合料冻融劈裂试验”方法测定的劈裂强度比不应小于80%。三、sbs沥青混合料的施工 sbs沥青是一种以弹性塑胶类改性沥青，正确使用可以显著提高沥青面层的抗车辙性能，增加耐久性，增加抗老化能力，延长公路的寿命。与ah-70基质沥青相比，sbs沥青的粘度和软化点显著增加，sbs沥青的运输储存和路面面层施工有一些与基质沥青不同的要求，只有正确使用才能达到预期效果。1、拌合、运输的技术要求 为保证沥青混合料的质量更稳定，沥青用量更准确，宜采用间隙式拌和机拌和。拌和必须均匀，只有sbs沥青改性剂完全分散在沥青中，才能充分发挥其效能，对于密级配（ac-13i）混合料，应做到拌合后的混合料均匀一致，无细料和粗料分离及花白、结成团块的现象。由于sbs改性沥青混合料的施工温度要求较高，建议拌合温度控制在160,运输车必须加盖篷布或其它保温材料，防止结合料表面结硬，为确保摊铺连续以及平整度大小符合技术规范要求，必须保证摊铺机前至少两辆车等待卸料，决不能出现摊铺机等车的现象。其余要求应满足改性沥青路面施工技术规范的技术要求。2、摊铺的技术要求 sbs沥青混合料在摊铺时应尽量连续不断的施工，以减少摊铺机和压路机的停顿，应尽量减少橫缝，提高其面层平整度。为提高路面的平整度，表面层宜采用摊铺前后保持相同高差的雪橇式摊铺厚度控制方式。由于sbs沥青粘度较大，粘附力强，用部分摊铺机的后雪橇是胶轮式结构，胶轮易粘附混合料细颗粒，影响平整度，所以摊铺机后雪橇是胶轮式结构的必须改成钢滑靴式结构。摊铺速度应控制在2米/分钟，做到缓慢、均匀、连续不间断地摊铺，禁止随意变换速度或中途停顿。 提高摊铺过程中的预压密实度。改性沥青sbs混合料在高温状态下主要是靠粗集料的嵌挤作用，可适当提高夯锤振捣频率，使剩余压实系数减少，初压的痕迹也极小，进而确保路面的最终平整度。3、碾压的技术要求 对于密级配型混合料，其适宜的碾压温度范围是130150，其最终碾压温度不低于110。sbs沥青混合料的压实工艺本着以下原则进行：按照“紧跟、慢压、高频、低幅”“碾压八字方针进行碾压，压路机必须紧跟摊铺机的后面，只有在高温条件下碾压才能取得更好的效果，压实速度控制在45km/h。碾压速度均衡，倒退时关闭振动，方向要逐渐地改变，不许拧着弯行走，对每一道碾压起点或终点可稍微扭弯碾压，消除碾压接头轮迹。决不允许在新铺沥青混合料上转向、调头、左右移动位置。突然刹车或停车休息，通过南二路第一、二合同段sbs沥青试验段，确定的压实工艺为dd110或dd130压路机23档各碾压3遍，即初压1遍，高频低幅振动碾压2遍，终压2遍。特别注意：施工时若发现压路机粘轮时，用洗衣粉水较好。4、sbs沥青混合料的质量控制 对于沥青面层混合料，现场的压实效果应采用空隙率和压实度双向控制。空隙率计算所需的最大理论密度以每天实测为准，测试按照“沥青路面混合料最大相对密度试验（真空法）（t071193）”进行。现场沥青混合料空隙率为3%6%。表面层沥青混合料压实度的检验，以实测芯样为准。四、结束语 随着sbs改性沥青在我国的进一步推广，必将在我国的道路建设中发挥重要作用，希望通过以上对sbs改性沥青在生产施工中应注意的施工技术要求，对大家有所帮助，以上不足之处，望各位同仁提出宝贵意见。译文：the sbs modified pitch match ratio design and discussion of construction technology the summary under good design match ratio and execution conditions, sbs pitch can make the durability on the pitch road surface and high-temperature stability obviously improve . this text will test the situation according to the construction of no. two in the south , will tell the construction specification requirement for the modified pitch of sbs briefly . first, sbs modified pitch summary the modified pitch of sbs is on the basis of original host pitch (ah-70 ), is it add 2.5% - 3.0% to mix, 4.0% sbs modify pharmaceutical, modify pitch after , compare with original pitch, its high-temperature viscidity increases, soften and click rising. under good design match ratio and execution conditions, the durability on the pitch road surface and high-temperature stability obviously improve. test while going on in a large number of rooms while the modified pitch of sbs produces, carry on the on-the-spot experiment to its technical indicator after production, experimental result indicate outside mix 3.0% modified pitch of sbs , soften some , needle enter degree index meet modified pitch standardize the request, can make the match ratio design of the pitch mixture with the modified pitch of sbs . second, the match ratio of the pitch mixture of sbs is designed in order to enable the mixture designed to reach the implementing effect, need to propose the following request from a great deal of respects , such as material requiring , construction craft , quality control standard and quality control method ,etc., hope to arouse attention. (1) , the raw materials are required collect the material thickly by 1-1: for the thick collection material of layer the modified pitch mixture, should adopt the broken stone or garrulous gravel , its specification of foot-path and quality requirement should accord with the regulation of pitch road surface construction technical specification of the highway (jtj032-94 ) 1.it should be clean , dry , has not weathered , not harmful to the impurity to collect the material thickly , and have certain hardness and intensity. 2.it should have good particle forms to collect the material that thick, when the broken gravel is used in the expressway , class i highway, should adopt the big gravel brokenly , and there should be two or more brokenness ones at least. 3, should choose the hard quality rock to collect the material in resisting the slippery top layer thickly (neutral or base igenous rock). because there are greater differences in the glueing the relay of hard quality rock and pitch, the thick seizing which collects the material and pitch should not be smaller than 4 grades . to 3- 5mm stone bits part it is relatively low because of the content, and this part forms the scary structure and has certain function to the pitch mixture, propose using the rock bits of hard quality (basalt). collect the material thinly by 1-2 the detailed collection material includes artificial sand , natural sand. each of pitch road surface should adopt the artificial sand as collecting the material thinly , it should be clean , dry , has not weathered , not harmful to the impurity to collect the material thinly, made up of proper particle, and have good seizing with the modified pitch, natural sand change with quality heavy(majority thick sand in being), relatively slick and sly form have, with the seizing difference of the pitch , exert a great influence on pitch mixture. to the expressway , class i highway pitch mixture, the content of the natural sand is unsuitable to exceed 20%, the stone bits powder of available 0-3mm replaces the natural sand. pack the material by 1-3 packing of layer should clean dry the mixture for modified pitch, specification requirement that quality should accord with the regulations of pitch road surface technical specification of the highway its. 1, the modified pitch mixture should be adopted the strong base rock (limestone , magmatic rock ) ,etc. to increase the building stones of swimming skill to rub the detailed ore powder that got to pack the material, ore it is dry clean , unsuitable to use mixture production do recovery powder , law of dust removal for powder to require. 2, while adopting the cement, subdueing the lime powder to make packing, its consumption is unsuitable to exceed 2% of the ore material general quantity. 3, does not recommend using and producing and arranging and retrieving the powder in the mixture one floor of mixture of pitch surface, when the plasticity index is smaller than 4 and hydrophilic coefficient is smaller than 0.8, through testing all right some use, retrieve 1/4 that cant exceed the ore powder general quantity of each one of consumption of powder. (2) , pitch mixture match ratio is designed: match ratio design of the modified pitch mixture, should follow the pitch road surface construction technical specification of the highway china mixes pitch mixture goal match ratio , match ratio of production that are designed of match ratio and tries mixing three stages that try paving about heat, confirm ore material one grade of mixing and best modified pitch consumption. 2-1 grades mixing pitch mixture match ratio is designed grade mixes and should adopt bei leifa to design , grade is worthy of choosing the principle: should fetch grade and mix lower limit to sift the hole in order to reach under mixture 2.36mm of model ac-13i. 2-2 powder expect than the amount smaller than 0.075mm content exerts a tremendous influence to the index of volume of pitch mixture and way with performance , mixture grade content to smaller than 0.075mm must consider thick to collect dust part that material should contain in mixing. require ore powder content exceed pitch content , smaller than 0.075mm part and ratio , pitch of content powder material than should exist 1- 1., should fetch the content of ore powder of one floor of mixture the pitch 4.5- 5. 2-3 precautions: the modified pitch mixes and arouses attention on the following problem in the design process with the material . shut and should hit real temperature according to the road surface construction technical specification of modified pitch and confirms according to glueing the warm relation curve of glued material of pitch in the mixing of a , mixing and material, mixing and shutting , hitting real temperature and should mix and shuts temperature with mix and shut the factory , rolls temperature live while carrying on the indoor match ratio design. propose that temperature sees the following form: the test of the modified pitch and construction temperature: temperature security mixes the pitch mixture it is not below 160 degrees centigrade to mix the temperature of shutting; press temperature and is not below 150 degrees centigrade for the first time; it is not below 140 degrees centigrade to reply the temperature of pressing; press temperature and is not below 120 degrees centigrade after all. b , test take a sample and mix the fashionable homogeneity that should guarantee the glued material of pitch , should prepare good glued material mix after shutting even going on taking a sample and preparation of mixture. the survey of c , mixture volume index will be unified , the survey mixing the pitch mixture and trying a density to security should adopt forms to do the law in unison . water and stability of d , modified pitch mixture should accord with two following index requests , should be taken and resisted to peel off the measure while reaching the request: (1), adopt marshall of pitch mixture steady degree test 48h soaked with water marshall steady degrees of test that method determine remain steady degree should lighter than 80% . ( 2) , adopt pitch mixture is it is it is it test intensity of splitting off that method determine than should 80% lighter than to split off to melt to freeze. third, construction of the pitch mixture of sbs sbs pitch one with elastic plastic modified pitch, correct to is it can improve story resist rut performance the pitch notably to use, increase durability, increase and resist aging ability , lengthen the life-span of the highway. compared with host pitch of ah-70, the viscidity and softenning and clicking increasing notably of sbs pitch , the transportation of sbs pitch has some requests different from host pitch to construct with floor the road surface to store, only use reaching the anticipated result correctly. 1, mix the specification requirement shut , transporting more steady for the quality of guaranteeing the pitch mixture, pitch consumption is more accurate, should adopt the interval type mixing and stir machine to mix and stir . it must be even to mix and stir, only sbs pitch modifies the pharmaceutical is totally dispersed in the pitch , could give full play to its efficiency , as to the thing that security mixes(ac-13i) the mixture, it is even and unanimous to mix the mixture after shutting, phenomenon that not so separated from thick material and black and white forming the group one as thin material . because the temperature of construction of the modified pitch mixture of sbs is expected relatively much, propose mixing the temperature of shutting to control in 160 degrees centigrade, the transport vechicle must put on tarpaulin or other heat insulator , prevent combining the material surface to form hard , it accords with the technical specification request that big or small in order to guarantee paving in succession and roughness, must guarantee that at least two cars waited to unload the material , the phenomenon that must not present the paver and wait for bus in front of the paver . the others require that should meet the specification requirement for the road surface construction technical specification of modified pitch . 2, the specification requirement paved successive construction that sbs pitch mixture should try ones best while paving, in order to reduce the stopping of the paver and road roller , should try ones best to reduce and sew , improve its roughness. in order to improve the roughness of the road surface, the surface layer should keep the sled type of the same discrepancy in elevation paving the control method of the thickness before and after adopting and paving . because sbs pitch viscidity is relatively great, it is strong to seize strength, it is the rubber tyer type structure to use the back sleds of some pavers, the rubber tyer is apt to seize the thin particle of mixture, influence the roughness, so the sled is that rubber tyer type structure must be made into the slippery boots type structure of steel after the paver. pave the speed and should be controlled in 2 meters per minute, make sure to pave without stopping slowly , evenly and in succession , forbid varying the speed or layovering at will . the ones that improved and paved in the course were pressed closely knit degree in advance. the modified pitch sbs mixture is mainly by collecting inlaying the function of crowding of material thickly under the high-temperature state, but improve the rammer hammer properly and shake the frequency of smashing , make surplus debulk coefficient reduce, the mark pressed for the first time is extremely small, and then guarantee the final roughness of the road surface . 3, the specification requirement rolled to the security mixing type mixture, its suitable rolling the temperature range is 130 degrees centigrade- 150 degrees centigrade, it roll temperature and is not lower than 110 degrees centigrade finally. the debulk craft of the pitch mixture of sbs goes on in line with the following principle: according to is it roll the eight character policy roll to follow keep , high frequency , low piece closely , not slow , the road roller must be followed closely in the back of the paver, only by rolling make better result under the high-temperature condition can it, the speed of debulk is controlled in 4- 5km/h. it is balanced to roll the speed, close vibration when falling back, the direction should change gradually, mustnt twist curved to walk, to roll starting point or terminal point